Indoor environment detection based on Wi-Fi smart hardware. The machine (smog set) could detect PM particles, temperature, humidity, noise. Through extensional modular unit, formaldehyde level, indoor pollutants due to interior decoration, domestic pollution and other environmental data could also be detected. The App can display indoor environment data, environmental abnormality warning, environmental improvement suggestions, personal health tips and other services. No matter where you are, you can always know the situation of the indoor environment.